The joint effect of tangible and non-tangible rewards on healthy food choices in children.

This study investigated how a combination of tangible and non-tangible rewards can alter health-related decisions made by children. Children chose between an unhealthy food option (a bowl of potato crisps) and a healthy food option (a bowl of grapes) on two occasions. In the first round, we manipulated the expected tangible reward and praise. The tangible reward was manipulated by means of a game that the child received upon choosing the healthy product, and the praise was manipulated by means of the teacher's applause and smiles if the child selected the healthy option. The second trial occurred three days after the first trial using the same food item options. Neither tangible rewards nor praise influenced the children's choices by themselves, but combining the two substantially increased the children's likelihood of selecting the healthy food choice. The data were consistent with a reattribution process akin to social labelling. Although initially externally motivated to select the healthy option, the children who received praise appeared to interpret their choice as internally motivated and therefore continued to select the healthy option even in the absence of reward.